1. Field of Invention
The present invention relates to a charger circuit, in particular to such charger circuit which includes at least two charging paths.
2. Description of Related Art
FIG. 1 shows a schematic diagram of a prior art charger circuit. As shown in FIG. 1, input power supplies a battery with a charging current, charging the battery through the charging path 11 of a charger circuit 10. A control circuit 12 obtains a battery feedback signal related to a battery charging status from the battery, and controls the charging path 11 accordingly such that when the battery charging status reaches a predetermined threshold, the charging path 11 is inactivated to finish the charging operation.
This conventional charger circuit charges the battery only by one charging path 11. In many applications, the charging path 11, the control circuit 12, and other circuits are integrated into an integrated circuit. Such conventional charger circuit is limited by the over temperature protection mechanism of the circuit; that is, the battery cannot be charged with a large current. Therefore, the charging time is long, and the charging efficiency is poor. Furthermore, due to heat dissipation issue of the charging path 11, the efficiency of the charging circuit 10 is further degraded.
In view of above, the present invention overcomes the foregoing defects by putting forth a charger circuit including at least two charging paths. The charger circuit can optimally select and adjust the charging paths according to the charging status and the environment temperature so as to improve the efficiency of the charger circuit and the issue of the over temperature protection, while it does not need a complicated the current design.